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A073600
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Least n^k with same leading decimal digit as n, k>1.
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3
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1, 256, 387420489, 4096, 59604644775390625, 60466176, 79792266297612001, 8589934592, 984770902183611232881, 100, 121, 144, 169, 196, 11390625, 1048576, 1419857, 104976, 130321, 25600000000, 278218429446951548637196401
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history;
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internal format)
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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a(4)=4096, as 4096=4^6 is the least power of 4 with initial digit =4: 4^2=16, 4^3=64, 4^4=256 and 4^5=1024; A073601(4)=6.
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MAPLE
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f:= proc(n) local t, k, m;
t:= floor(n/10^ilog10(n));
for k from 2 do
m:= n^k;
if floor(m/10^ilog10(m)) = t then return m fi
od
end proc:
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MATHEMATICA
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fi[n_] := First[IntegerDigits[n]]; Table[k = 2; While[fi[x = n^k] != fi[n], k++]; x, {n, 21}] (* Jayanta Basu, Jul 02 2013 *)
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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